129. BigDecimal Division

This is a follow-up on 126. BigDecimal addition

In this problem, you are asked to implement the division of two decimals with arbitrary digits.

divide(  '100000000000000.1',   '-0.001')// '-100000000000000100'divide(  '-0.123',   '-0.00971')// '12.66735324407826982492'

1. This problem covers 115. implement BigInt division.
2. trailing zeroes in the result should be removed.
3. return the result with max 20 digit fraction part, rest be truncated.